Patent application title: ORGANIC ELECTROLUMINESCENCE DEVICE

Abstract:

An organic electroluminescence device includes an anode; a cathode; and at
least one organic layer, which includes a light-emitting layer being
provided between the anode and the cathode and containing at least one
light-emitting material, and which contains at least one compound
represented by formula (I):
##STR00001##
wherein each of A11, A12, A13, A14 and A15
represents an N atom or C--R11, and the number of N atoms
represented by A11 to A15 is 1 or 2; R11 represents a
hydrogen atom or a substituent, and at least one of R11 represents
an aryl group or an aromatic heterocyclic group; Q11 represents a
monocyclic aryl group or an aromatic heterocyclic group; R12
represents an alkyl group; and each of n, m and l represents an integer
of from 0 to 4, provided that n is 1 or more, n+m is 2 or more, and n+m+l
is 4.

Claims:

1. An organic electroluminescence device comprising:an anode;a cathode;
andat least one organic layer,whereinthe at least one organic layer
comprises a light-emitting layer being provided between the anode and the
cathode and containing at least one light-emitting material, andthe at
least one organic layer contains at least one compound represented by
formula (I): ##STR00094## whereineach of A11, A12, A13,
A14 and A15 represents an N atom or C--R11, and the number
of N atoms represented by A11 to A15 is an integer of 1 or
2;R11 represents a hydrogen atom or a substituent, and at least one
of R11 represents an aryl group or an aromatic heterocyclic
group;when a plurality of partial structures represented by the following
formula (I-a) are present, each partial structure (I-a) may be the same
with or different from every other (I-a);Q11 represents a monocyclic
aryl group or an aromatic heterocyclic group, and each Q11 may be
the same with or different from every other Q11;R12 represents
an alkyl group, and each R12 may be the same with or different from
every other R12; andeach of n, m and l represents an integer of from
0 to 4, provided that n is an integer of 1 or more, n+m is an integer of
2 or more, and n+m+l is 4: ##STR00095##

2. The organic electroluminescence device as claimed in claim 1,
whereinthe compound represented by formula (I) is a compound represented
by formula (II): ##STR00096## whereineach of A21, A22,
A23, A24 and A25 represents an N atom or C--R21, and
the number of N atom represented by A21 to A25 is 1;R21
represents a hydrogen atom or a substituent, and at least one of R21
represents an aryl group or an aromatic heterocyclic group;when a
plurality of partial structures represented by the following formula
(II-a) are present, each partial structure (II-a) may be the same with or
different from every other (II-a);Q21 represents a monocyclic aryl
group or an aromatic heterocyclic group, and each Q21 may be the
same with or different from every other Q21;R22 represents an
alkyl group, and each R22 may be the same with or different from
every other R22; andeach of n, m and l represents an integer of from
0 to 4, provided that n is an integer of 1 or more, n+m is an integer of
2 or more, and n+m+l is 4: ##STR00097##

3. The organic electroluminescence device as claimed in claim 2,
whereinthe compound represented by formula (II) is a compound represented
by formula (III): ##STR00098## whereinR31 represents a hydrogen atom
or a substituent, and at least one of R31 represents an aryl group
or an aromatic heterocyclic group;when a plurality of partial structures
represented by the following formula (III-a) are present, each partial
structure (III-a) may be the same with or different from every other
(II-a);Q31 represents a monocyclic aryl group or an aromatic
heterocyclic group, and each Q31 may be the same with or different
from every other Q31;R32 represents an alkyl group, and each
R32 may be the same with or different from every other R32;
andeach of n, m and l represents an integer of from 0 to 4, provided that
n is an integer of 1 or more, n+m is an integer of 2 or more, and n+m+l
is 4: ##STR00099##

4. The organic electroluminescence device as claimed in claim 2,
whereinthe compound represented by formula (II) is a compound represented
by formula (IV): ##STR00100## whereinR41 represents a hydrogen atom
or a substituent, and at least one of R41 represents an aryl group
or an aromatic heterocyclic group;when a plurality of partial structures
represented by the following formula (IV-a) are present, each partial
structure (IV-a) may be the same with or different from every other
(IV-a);Q41 represents a monocyclic aryl group or an aromatic
heterocyclic group, and each Q41 may be the same with or different
from every other Q41;R42 represents an alkyl group, and each
R42 may be the same with or different from every other R42;
andeach of n, m and l represents an integer of from 0 to 4, provided that
n is an integer of 1 or more, n+m is an integer of 2 or more, and n+m+l
is 4: ##STR00101##

5. The organic electroluminescence device as claimed in claim 2,
whereinthe compound represented by formula (II) is a compound represented
by formula (V): ##STR00102## whereinR51 represents a hydrogen atom
or a substituent, and at least one of R51 represents an aryl group
or an aromatic heterocyclic group;when a plurality of partial structures
represented by the following formula (V-a) are present, each partial
structure (V-a) may be the same with or different from every other
(V-a);Q51 represents a monocyclic aryl group or an aromatic
heterocyclic group, and each Q51 may be the same with or different
from every other Q51;R52 represents an alkyl group, and each
R2 may be the same with or different from every other R52;
andeach of n, m and l represents an integer of from 0 to 4, provided that
n is an integer of 1 or more, n+m is an integer of 2 or more, and n+m+l
is 4; ##STR00103##

6. The organic electroluminescence device as claimed in claim 1,
whereinthe compound represented by formula (I) has a glass transition
temperature of 130.degree. C. or more and 450.degree. C. or less.

8. The organic electroluminescence device as claimed in claim 1,
whereinthe at least one light-emitting material comprises a
phosphorescent material.

9. The organic electroluminescence device as claimed in claim 8,
whereinthe phosphorescent material is an iridium complex or a platinum
complex.

10. The organic electroluminescence device as claimed in claim 9, wherein
the platinum complex is a platinum complex represented by formula (C-1):
##STR00104## whereineach of Q1, Q2, Q3 and Q4
independently represents a ligand to coordinate to Pt; andeach of
L1, L2 and L3 independently represents a single bond or a
divalent linking group.

12. The organic electroluminescence device as claimed in claim 1,
whereinthe at least one organic layer further comprises at least one
electron transporting layer being provided between the light-emitting
layer and the cathode, andthe at least one electron transporting layer
contains the compound represented by formula (I).

[0004]Since organic electroluminescence devices (organic EL devices) are
capable of obtaining emission of light of high luminance by low voltage
driving, they are actively researched and developed. An organic EL device
generally comprises a pair of electrodes and an organic layer between the
pair of electrodes, electrons injected from the cathode and holes
injected from the anode are recombined in the organic layer, and
generated energy of exciton is used for emission of light.

[0005]In recent years, increment in efficiency of devices has been
advanced by the use of phosphorescent materials. As the phosphorescent
materials, iridium complexes and platinum complexes are described in U.S.
Pat. No. 6,303,238. However, devices that satisfy compatibility of high
efficiency and high durability are not yet developed.

[0006]For the intention of obtaining materials of high durability, organic
EL devices using a compound having an electron-defective
nitrogen-containing heterocyclic group as the material are described in
JP-A-2003-138251, JP-A-2004-103463 (The term "JP-A" as used herein refers
to an "unexamined published Japanese patent application".) and Chemistry
of Materials, Vol. 10, pp. 3620-3625 (1998).

SUMMARY OF THE INVENTION

[0007]However, the materials used in these techniques have condensed
rings, long in conjugated system, and low in the lowest excitation
triplet (T1 level) of molecules, so that these devices are
susceptible to quenching of phosphorescence and luminous efficiency
lowers. Further, materials high in T1 level are low in electron
affinity (Ea), and injection of electrons to the light-emitting layer and
transportation are not sufficient, driving voltage of the devices and
electric power consumption are high, so that luminous efficiency lowers.
Accordingly, compatibility of high T1 level and high Ea is not
realized yet.

[0008]An object of the invention is to provide an organic
electroluminescence device high in luminous efficiency and durability.
Another object is to provide a silicon-linking type nitrogen-containing
heterocyclic group compound suitable for use in the organic EL device.

[0009]As a result of earnest examinations by the present inventors to
solve the above problems, it has been found that the above problems are
dissolved by the use of an organic EL device containing a silicon-linking
type nitrogen-containing heterocyclic group compound having a special
structure in the organic layer. That is, the present invention has been
achieved by the following means.

(1) An organic electroluminescence device comprising:

[0010]an anode;

[0011]a cathode; and

[0012]at least one organic layer,

[0013]wherein

[0014]the at least one organic layer comprises a light-emitting layer
being provided between the anode and the cathode and containing at least
one light-emitting material, and

[0015]the at least one organic layer contains at least one compound
represented by formula (I):

##STR00002##

[0016]wherein

[0017]each of A11, A12, A13, A4 and A15
represents an N atom or C--R11, and the number of N atoms
represented by A11 to A15 is an integer of 1 or 2;

[0018]R11 represents a hydrogen atom or a substituent, and at least
one of R11 represents an aryl group or an aromatic heterocyclic
group;

[0019]when a plurality of partial structures represented by the following
formula (I-a) are present, each partial structure (I-a) may be the same
with or different from every other (I-a);

[0020]Q11 represents a monocyclic aryl group or an aromatic
heterocyclic group, and each Q11 may be the same with or different
from every other Q11;

[0021]R12 represents an alkyl group, and each R12 may be the
same with or different from every other R12; and

[0022]each of n, m and l represents an integer of from 0 to 4, provided
that n is an integer of 1 or more, n+m is an integer of 2 or more, and
n+m+l is 4:

##STR00003##

(2) The organic electroluminescence device as described in (1), wherein

[0023]the compound represented by formula (I) is a compound represented by
formula (II):

##STR00004##

[0024]wherein

[0025]each of A21, A22 A23, A24 and A25
represents an N atom or C--R21, and the number of N atom represented
by A21 to A25 is 1;

[0026]R21 represents a hydrogen atom or a substituent, and at least
one of R21 represents an aryl group or an aromatic heterocyclic
group;

[0027]when a plurality of partial structures represented by the following
formula (II-a) are present, each partial structure (II-a) may be the same
with or different from every other (II-a);

[0028]Q21 represents a monocyclic aryl group or an aromatic
heterocyclic group, and each Q21 may be the same with or different
from every other Q21;

[0029]R22 represents an alkyl group, and each R22 may be the
same with or different from every other R22; and

each of n, m and l represents an integer of from 0 to 4, provided that n
is an integer of 1 or more, n+m is an integer of 2 or more, and n+m+l is
4:

##STR00005##

(3) The organic electroluminescence device as described in (2), wherein

[0030]the compound represented by formula (II) is a compound represented
by formula (III):

##STR00006##

[0031]wherein

[0032]R31 represents a hydrogen atom or a substituent, and at least
one of R31 represents an aryl group or an aromatic heterocyclic
group;

[0033]when a plurality of partial structures represented by the following
formula (III-a) are present, each partial structure (III-a) may be the
same with or different from every other (III-a);

[0034]Q31 represents a monocyclic aryl group or an aromatic
heterocyclic group, and each Q31 may be the same with or different
from every other Q31;

[0035]R32 represents an alkyl group, and each R32 may be the
same with or different from every other R32; and

[0036]each of n, m and l represents an integer of from 0 to 4, provided
that n is an integer of 1 or more, n+m is an integer of 2 or more, and
n+m+l is 4:

##STR00007##

(4) The organic electroluminescence device as described in (2), wherein

[0037]the compound represented by formula (II) is a compound represented
by formula (IV):

##STR00008##

[0038]wherein

[0039]R41 represents a hydrogen atom or a substituent, and at least
one of R41 represents an aryl group or an aromatic heterocyclic
group;

[0040]when a plurality of partial structures represented by the following
formula (IV-a) are present, each partial structure (IV-a) may be the same
with or different from every other (IV-a);

[0041]Q41 represents a monocyclic aryl group or an aromatic
heterocyclic group, and each Q41 may be the same with or different
from every other Q41;

[0042]R42 represents an alkyl group, and each R42 may be the
same with or different from every other R42; and

[0043]each of n, m and l represents an integer of from 0 to 4, provided
that n is an integer of 1 or more, n+m is an integer of 2 or more, and
n+m+l is 4:

##STR00009##

(5) The organic electroluminescence device as described in (2), wherein

[0044]the compound represented by formula (II) is a compound represented
by formula (V):

##STR00010##

[0045]wherein

[0046]R51 represents a hydrogen atom or a substituent, and at least
one of R51 represents an aryl group or an aromatic heterocyclic
group;

[0047]when a plurality of partial structures represented by the following
formula (V-a) are present, each partial structure (V-a) may be the same
with or different from every other (V-a);

[0048]Q51 represents a monocyclic aryl group or an aromatic
heterocyclic group, and each Q51 may be the same with or different
from every other Q51;

[0049]R52 represents an alkyl group, and each R52 may be the
same with or different from every other R52; and

each of n, m and l represents an integer of from 0 to 4, provided that n
is an integer of 1 or more, n+m is an integer of 2 or more, and n+m+l is
4:

##STR00011##

(6) The organic electroluminescence device as described in (1), wherein
the compound represented by formula (I) has a glass transition
temperature of 130° C. or more and 450° C. or less.(7) The
organic electroluminescence device as described in (1), wherein

[0059]The organic electroluminescence device in the invention is an
organic electroluminescence device comprising an anode; a cathode; and at
least one organic layer, wherein the at least one organic layer comprises
a light-emitting layer being provided between the anode and the cathode
and containing at least one light-emitting material, and the at least one
organic layer contains at least one compound represented by formula (I):

##STR00013##

[0060]In formula (I), each of A11, A12, A13, A14 and
A15 represents an N atom or C--R11, and the number of N atoms
represented by A11 to A15 is an integer of 1 or 2; R11
represents a hydrogen atom or a substituent, and at least one of R11
represents an aryl group or an aromatic heterocyclic group, when a
plurality of partial structures represented by the following formula
(I-a) are present, each partial structure (I-a) may be the same with or
different from every other (I-a); Q11 represents a monocyclic aryl
group or an aromatic heterocyclic group, and each Q11 may be the
same with or different from every other Q11; R12 represents an
alkyl group, and each R12 may be the same with or different from
every other R12; and each of n, m and l represents an integer of
from 0 to 4, provided that n is an integer of 1 or more, n+m is an
integer of 2 or more, and n+m+l is 4.

##STR00014##

[0061]That is, the organic electroluminescence device in the invention has
at least one organic light-emitting layer (the light-emitting layer).
Further, as the organic layers other than the light-emitting layer, a
hole injecting layer, a hole transporting layer, an electron-blocking
layer, an exciton-blocking layer, a hole-blocking layer, an electron
transporting layer, an electron injecting layer, and a protective layer
may be arbitrarily arranged, and each layer may unite functions of other
layers. Further, each layer may be composed of a plurality of layers.

[0062]The organic electroluminescence device in the invention may be the
one utilizing emission of light from excitation singlet (fluorescence),
or may be the one utilizing emission of light from excitation triplet
(phosphorescence), but the one using phosphorescence is preferred from
the viewpoint of luminous efficiency.

[0063]The light-emitting layer of the organic electroluminescence device
in the invention is preferably composed of at least one light-emitting
material and at least one host material. Here, the host material means a
material other than the light-emitting material of the materials
constituting the light-emitting layer, which has at least one function of
a function of dispersing a light-emitting material and maintaining the
dispersion in the light-emitting layer, a function of receiving holes
from the anode and a hole transporting layer, a function of receiving
electrons from the cathode and an electron transporting layer, a function
of transporting at least one of holes and electrons, a function of
offering the place of recombination of holes and electrons, a function of
transporting the energy of exciton generated by the recombination to the
light-emitting material, and a function of transporting at least one of
holes and electrons to the light-emitting material.

[0064]The compounds of the invention may be contained in any layer of the
organic layers, and may be contained in a plurality of layers, but they
are preferably contained in a light-emitting layer, a hole blocking
layer, an electron transporting layer, or an electron injecting layer,
more preferably contained in a light-emitting layer, or an electron
transporting layer, still more preferably contained in a light-emitting
layer, and most preferably contained in a light-emitting layer as host
materials. When the compounds of the invention are contained in a
light-emitting layer as host materials, the content of the compounds of
the invention in the light-emitting layer is preferably from 50 to 99.9
mass %, and more preferably from 60 to 99 mass %. Further, when the
compounds of the invention are contained in a hole blocking layer, an
electron transporting layer, or an electron injecting layer, the content
of the compounds of the invention in each layer is preferably from 70 to
100%, more preferably from 85 to 100%, and most preferably from 99 to
100%. Further, when an electron transporting layer consists of two or
more layers, it is sufficient for any one layer to contain the compounds
of the invention.

[0065]The compound represented by formula (I) will be explained in detail
below.

##STR00015##

[0066]In formula (I), each of A11, A12, A13, A14 and
A15 represents an N atom or C--R11, and the number of N atoms
represented by A11 to A15 is an integer of 1 or 2. R11
represents a hydrogen atom or a substituent, and at least one of R11
represents an aryl group or an aromatic heterocyclic group. When there
are present a plurality of partial structures represented by the
following formula (I-a), each partial structure (I-a) may be the same
with or different from every other (I-a). Q11 represents a
monocyclic aryl group or an aromatic heterocyclic group, and each
Q11 may be the same with or different from every other Q11.
R12 represents an alkyl group, and each R12 may be the same
with or different from every other R12. Each of n, m and l
represents an integer of from 0 to 4, provided that n is an integer of l
or more, n+m is an integer of 2 or more, and n+m+l is 4.

##STR00016##

[0067]Formula (I) is described below. Each of A11 to A15
represents an N atom or C--R11, and the number of N atoms
represented by A11 to A15 is an integer of 1 or 2, and the
position thereof is not especially restricted. R11 represents a
hydrogen atom or a substituent, and at least one of R11 represents
an aryl group or an aromatic heterocyclic group. Each R11 may be the
same with or different from every other R11. Further, a plurality of
R11 are not linked to each other to form a condensed ring. As the
examples of the substituents represented by R11, substituent group A
described below is applicable to the substituents.

Substituent Group A:

[0068]An alkyl group (preferably having from 1 to 30 carbon atoms, more
preferably from 1 to 20 carbon atoms, and especially preferably from 1 to
10 carbon atoms, e.g., methyl, ethyl, isopropyl, tert-butyl, n-octyl,
n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc., are
exemplified), an alkenyl group (preferably having from 2 to 30 carbon
atoms, more preferably from 2 to 20 carbon atoms, and especially
preferably from 2 to 10 carbon atoms, e.g., vinyl, allyl, 2-butenyl,
3-pentenyl, etc., are exemplified), an alkynyl group (preferably having
from 2 to 30 carbon atoms, more preferably from 2 to 20 carbon atoms, and
especially preferably from 2 to 10 carbon atoms, e.g., propargyl,
3-pentynyl, etc., are exemplified), an aryl group (preferably having from
6 to 30 carbon atoms, more preferably from 6 to 20 carbon atoms, and
especially preferably from 6 to 12 carbon atoms, e.g., phenyl,
p-methylphenyl, naphthyl, anthranyl, etc., are exemplified), an amino
group (preferably having from 0 to 30 carbon atoms, more preferably from
0 to 20 carbon atoms, and especially preferably from 0 to 10 carbon
atoms, e.g., amino, methylamino, dimethylamino, diethylamino,
dibenzylamino, diphenylamino, ditolylamino, etc., are exemplified), an
alkoxy group (preferably having from 1 to 30 carbon atoms, more
preferably from 1 to 20 carbon atoms, and especially preferably from 1 to
10 carbon atoms, e.g., methoxy, ethoxy, butoxy, 2-ethylhexyloxy, etc.,
are exemplified), an aryloxy group (preferably having from 6 to 30 carbon
atoms, more preferably from 6 to 20 carbon atoms, and especially
preferably from 6 to 12 carbon atoms, e.g., phenyloxy, 1-naphthyloxy,
2-naphthyloxy, etc., are exemplified), a heterocyclic oxy group
(preferably having from 1 to 30 carbon atoms, more preferably from 1 to
20 carbon atoms, and especially preferably from 1 to 12 carbon atoms,
e.g., pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc., are
exemplified), an acyl group (preferably having from 2 to 30 carbon atoms,
more preferably from 2 to 20 carbon atoms, and especially preferably from
2 to 12 carbon atoms, e.g., acetyl, benzoyl, formyl, pivaloyl, etc., are
exemplified), an alkoxycarbonyl group (preferably having from 2 to 30
carbon atoms, more preferably from 2 to 20 carbon atoms, and especially
preferably from 2 to 12 carbon atoms, e.g., methoxycarbonyl,
ethoxycarbonyl, etc., are exemplified), an aryloxycarbonyl group
(preferably having from 7 to 30 carbon atoms, more preferably from 7 to
20 carbon atoms, and especially preferably from 7 to 12 carbon atoms,
e.g., phenyloxycarbonyl, etc., are exemplified), an acyloxy group
(preferably having from 2 to 30 carbon atoms, more preferably from 2 to
20 carbon atoms, and especially preferably from 2 to 10 carbon atoms,
e.g., acetoxy, benzoyloxy, etc., are exemplified), an acylamino group
(preferably having from 2 to 30 carbon atoms, more preferably from 2 to
20 carbon atoms, and especially preferably from 2 to 10 carbon atoms,
e.g., acetylamino, benzoylamino, etc., are exemplified), an
alkoxycarbonylamino group (preferably having from 2 to 30 carbon atoms,
more preferably from 2 to 20 carbon atoms, and especially preferably from
2 to 12 carbon atoms, e.g., methoxycarbonylamino, etc., are exemplified),
an aryloxycarbonylamino group (preferably having from 7 to 30 carbon
atoms, more preferably from 7 to 20 carbon atoms, and especially
preferably from 7 to 12 carbon atoms, e.g., phenyloxycarbonylamino, etc.,
are exemplified), a sulfonylamino group (preferably having from 1 to 30
carbon atoms, more preferably from 1 to 20 carbon atoms, and especially
preferably from 1 to 12 carbon atoms, e.g., methanesulfonylamino,
benzenesulfonylamino, etc., are exemplified), a sulfamoyl group
(preferably having from 0 to 30 carbon atoms, more preferably from 0 to
20 carbon atoms, and especially preferably from 0 to 12 carbon atoms,
e.g., sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl,
etc., are exemplified), a carbamoyl group (preferably having from 1 to 30
carbon atoms, more preferably from 1 to 20 carbon atoms, and especially
preferably from 1 to 12 carbon atoms, e.g., carbamoyl, methylcarbamoyl,
diethylcarbamoyl, phenylcarbamoyl, etc., are exemplified), an alkylthio
group (preferably having from 1 to 30 carbon atoms, more preferably from
1 to 20 carbon atoms, and especially preferably from 1 to 12 carbon
atoms, e.g., methylthio, ethylthio, etc., are exemplified), an arylthio
group (preferably having from 6 to 30 carbon atoms, more preferably from
6 to 20 carbon atoms, and especially preferably from 6 to 12 carbon
atoms, e.g., phenylthio, etc., are exemplified), a heterocyclic thio
group (preferably having from 1 to 30 carbon atoms, more preferably from
1 to 20 carbon atoms, and especially preferably from 1 to 12 carbon
atoms, e.g., pyridylthio, 2-benzimizolylthio, 2-benzoxazolylthio,
2-benzothiazolylthio, etc., are exemplified), a sulfonyl group
(preferably having from 1 to 30 carbon atoms, more preferably from 1 to
20 carbon atoms, and especially preferably from 1 to 12 carbon atoms,
e.g., mesyl, tosyl, etc., are exemplified), a sulfinyl group (preferably
having from 1 to 30 carbon atoms, more preferably from 1 to 20 carbon
atoms, and especially preferably from 1 to 12 carbon atoms, e.g.,
methanesulfinyl, benzenesulfinyl, etc., are exemplified), a ureido group
(preferably having from 1 to 30 carbon atoms, more preferably from 1 to
20 carbon atoms, and especially preferably from 1 to 12 carbon atoms,
e.g., ureido, methylureido, phenylureido, etc., are exemplified), a
phosphoric acid amido group (preferably having from 1 to 30 carbon atoms,
more preferably from 1 to 20 carbon atoms, and especially preferably from
1 to 12 carbon atoms, e.g., diethylphosphoric acid amido,
phenylphosphoric acid amido, etc., are exemplified), a hydroxyl group, a
mercapto group, a halogen atom (e.g., a fluorine atom, a chlorine atom, a
bromine atom, an iodine atom), a cyano group, a sulfo group, a carboxyl
group, a nitro group, a hydroxamic acid group, a sulfino group, a
hydrazino group, an imino group, a heterocyclic group (also including an
aromatic heterocyclic group, preferably having from 1 to 30 carbon atoms,
and more preferably from 1 to 12 carbon atoms, and as the hetero atoms,
e.g., a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom,
a silicon atom, a selenium atom, and a tellurium atom are exemplified,
specifically, e.g., pyridyl, pyrazinyl, pyrimidyl, pyridazinyl, pyrrolyl,
pyrazolyl, triazolyl, imidazolyl, oxazolyl, thiazolyl, isoxazolyl,
isothiazolyl, quinolyl, furyl, thienyl, selenophenyl, tellurophenyl,
piperidyl, piperidino, morpholino, pyrrolidyl, pyrrolidino, benzoxazolyl,
benzimidazolyl, benzothiazolyl, a carbazolyl group, an azepinyl group, a
silolyl group, etc., are exemplified), a silyl group (preferably having
from 3 to 40 carbon atoms, more preferably from 3 to 30 carbon atoms, and
especially preferably from 3 to 24 carbon atoms, e.g., trimethylsilyl,
triphenylsilyl, etc., are exemplified), a silyloxy group (preferably
having from 3 to 40 carbon atoms, more preferably from 3 to 30 carbon
atoms, and especially preferably from 3 to 24 carbon atoms, e.g.,
trimethylsilyloxy, triphenylsilyloxy, etc., are exemplified), and a
phosphoryl group (e.g., a diphenylphosphoryl group, a dimethylphosphoryl
group, etc., are exemplified) are exemplified. These substituents may
further be substituted, and the substituents selected from substituent
group A described above can be exemplified as further substituents.

[0069]Each R11 may be the same with or different from every other
R11. R11 may further have a substituent, and substituent group
A is applicable to the substituent.

[0070]The substituents represented by R11 are preferably a hydrogen
atom, an alkyl group, an aryl group, a fluorine group, an amino group, an
alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio
group, an arylthio group, a heterocyclic thio group, a cyano group, a
heterocyclic group, a silyl group, and a silyloxy group, more preferably
a hydrogen atom, an alkyl group, an aryl group, a fluorine group, a cyano
group, a silyl group, and a heterocyclic group, still more preferably a
hydrogen atom, an alkyl group, an aryl group, a fluorine group, a cyano
group, a silyl group, and a heterocyclic group, and especially preferably
a hydrogen atom, an alkyl group, an aryl group, and a heterocyclic group.
These substituents are preferred for capable of improving chemical and
thermal stability of the compound represented by formula (I).

[0071]The ring of at least one aryl group or aromatic heterocyclic group
contained in R11 is not especially restricted, but is preferably a
4- to 10-membered ring, more preferably a 5- to 7-membered ring, still
more preferably a 5- or 6-membered ring, and especially preferably a
6-membered ring. The hetero atoms contained in the aromatic heterocyclic
ring are not especially restricted, but an aromatic heterocyclic ring
containing nitrogen, oxygen, sulfur, selenium, silicon, germanium or
phosphorus is preferred, nitrogen, oxygen or sulfur is more preferred,
nitrogen or oxygen is still more preferred, and nitrogen is especially
preferred. The number of hetero atoms contained in one aromatic
heterocyclic ring is not especially restricted, but is preferably from 1
to 3.

[0072]The specific examples of the rings of at least one aryl group or
aromatic heterocyclic group contained in R11 include a benzene ring
group, a pyridine ring group, a pyrazine ring group, a pyrimidine ring
group, a triazine ring group, a pyridazine ring group, a pyrrole ring
group, a pyrazole ring group, an imidazole ring group, a triazole ring
group, an oxazole ring group, an oxadiazole ring group, a thiazole ring
group, a thiadiazole ring group, a furan ring group, a thiophene ring
group, a selenophene ring group, a silol ring group, a germole ring
group, and a phosphole ring group. The above substituents may further
have a substituent.

[0073]The preferred examples of the rings of at least one aryl group or
aromatic heterocyclic group contained in R11 include a benzene ring,
a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazine ring, a
pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, an
oxazole ring, a thiazole ring, a furan ring, and a thiophene ring, more
preferably a benzene ring, a pyridine ring, a pyrazine ring, a pyrrole
ring, a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole
ring, and a thiophene ring, still more preferably a benzene ring, a
pyridine ring, a pyrazine ring, a pyrazole ring, an imidazole ring, and a
thiophene ring, and especially preferably a benzene ring, a pyridine
ring, and a pyrazine ring.

[0074]The ring of the monocyclic aryl group or aromatic heterocyclic group
represented by Q11 is not especially restricted, but from the
aspects of maintaining chemical stability and high excitation triplet
energy level, a 4- to 10-membered ring is preferred, a 5- to 7-membered
ring is more preferred, a 5- or 6-membered ring is still more preferred,
and a 6-membered ring is especially preferred. The hetero atoms contained
in the ring of the aromatic heterocyclic group represented by Q11
are not especially restricted, but an aromatic heterocyclic ring
containing nitrogen, oxygen, sulfur, selenium, silicon, germanium or
phosphorus is preferred, nitrogen, oxygen or sulfur is more preferred,
nitrogen or oxygen is still more preferred, and nitrogen is especially
preferred. The number of hetero atoms contained in one aromatic
heterocyclic ring is not especially restricted, but the number of from 1
to 3 is preferred.

[0075]The specific examples of the rings of the monocyclic aryl group or
aromatic heterocyclic group represented by Q11 include a benzene
ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazine
ring, a pyridazine ring, a pyrrole ring, a pyrazole ring, an imidazole
ring, a triazole ring, an oxazole ring, an oxadiazole ring, a thiazole
ring, a thiadiazole ring, a furan ring, a thiophene ring, a selenophene
ring, a silol ring, a germole ring, and a phosphole ring.

[0076]The aryl group or aromatic heterocyclic group formed of Q11 may
have a substituent, and substituent group A described above is applicable
to the substituents, However, an aryl ring or an aromatic heterocyclic
ring is not substituted.

[0077]The rings of the monocyclic aryl group or aromatic heterocyclic
group represented by Q11 include preferably a benzene ring, a
pyridine ring, a pyrazine ring, a pyrimidine ring, a triazine ring, a
pyridazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a
triazole ring, an oxazole ring, an oxadiazole ring, a thiazole ring, a
thiadiazole ring, a furan ring, a thiophene ring, a selenophene ring, a
silol ring, a germole ring, and a phosphole ring, more preferably a
benzene ring, a pyridine ring, a pyrazine ring, a pyrrole ring, a
pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring, and a
thiadiazole ring, still more preferably a benzene ring, a pyridine ring,
a pyrazine ring, a pyrazole ring, an imidazole ring, and a thiadiazole
ring, and especially preferably a benzene ring, a pyridine ring and a
pyrazine ring.

[0078]The alkyl group represented by R12 may further have a
substituent, and substituent group A described above is applicable to the
substituent. Each R12 may be the same with or different from every
other R12. Since the alkyl group represented by R12 does not
contribute to electron transportation in the EL device, 1 that represents
the number of substitution of R12 is preferably zero.

[0079]As one of the preferred embodiments in the light of the improvement
of chemical stability, the compound represented by formula (I) is a
compound represented by the following formula (II).

##STR00017##

[0080]In formula (II), each of A21, A22, A23, A24 and
A25 represents an N atom or C--R21, and the number of N atom
represented by A21 to A25 is 1. R21 represents a hydrogen
atom or a substituent. At least one of R21 represents an aryl group
or an aromatic heterocyclic group. When there are present a plurality of
partial structures represented by the following formula (II-a), each
partial structure (II-a) may be the same with or different from every
other (II-a). Q21 represents a monocyclic aryl group or an aromatic
heterocyclic group. Each Q21 may be the same with or different from
every other Q21. R22 represents an alkyl group. Each R22
may be the same with or different from every other R22. Each of n, m
and l represents an integer of from 0 to 4, provided that n is an integer
of 1 or more, n+m is an integer of 2 or more, and n+m+l is 4.

##STR00018##

[0081]Formula (II) is described below. A21 to A25, R21,
R22, Q21, n, m and l respectively have the same meanings as
A11 to A15, R11, R12, Q11, n, m and l in formula
(I), and preferred ranges are also the same.

[0082]The compound represented by formula (II) is more preferably a
compound represented by formula (III), (IV) or (V) in view of the
improvement of chemical stability.

##STR00019##

[0083]In formula (III), R31 represents a hydrogen atom or a
substituent. At least one of R31 represents an aryl group or an
aromatic heterocyclic group. When there are present a plurality of
partial structures represented by the following formula (III-a), each
partial structure (III-a) may be the same with or different from every
other (III-a). Q31 represents a monocyclic aryl group or an aromatic
heterocyclic group. Each Q31 may be the same with or different from
every other Q31. R32 represents an alkyl group. Each R32
may be the same with or different from every other R32. Each of n, m
and l represents an integer of from 0 to 4, provided that n is an integer
of 1 or more, n+m is an integer of 2 or more, and n+m+l is 4.

##STR00020##

[0084]Formula (III) is described below. R31, R32, Q31, n, m
and l respectively have the same meanings as R21, R22,
Q21, n, m and l in formula (II), and preferred ranges are also the
same.

[0085]For maintaining high excitation triplet energy level, the compound
represented by formula (III) is more preferably a compound represented by
the following formula (III-b).

##STR00021##

[0086]In formula (III-b), R11 represents a hydrogen atom or a
substituent. At least one of R31 represents an aryl group or an
aromatic heterocyclic group. When there are present a plurality of
partial structures represented by the following formula (III-b)', each
partial structure (III-b)' may be the same with or different from every
other (III-b)'. Q31 represents a monocyclic aryl group or an
aromatic heterocyclic group. Each Q31 may be the same with or
different from every other Q31. Q32 represents an aryl group or
an aromatic heterocyclic group. R32 represents an alkyl group. Each
R32 may be the same with or different from every other R32.
Each of n, m and l represents an integer of from 0 to 4, provided that n
is an integer of 1 or more, n+m is an integer of 2 or more, and n+m+l is
4.

##STR00022##

[0087]Formula (III-b) is described below. R31, R32, Q31, n,
m and l respectively have the same meanings as R31, R32,
Q31, n, m and l in formula (III), and preferred ranges are also the
same.

[0088]The ring of the aryl group or aromatic heterocyclic group
represented by Q32 is not especially restricted, but from the
aspects of maintaining chemical stability and high excitation triplet
energy level, a 4- to 10-membered ring is preferred, a 5- to 7-membered
ring is more preferred, a 5- or 6-membered ring is still more preferred,
and a 6-membered ring is especially preferred. The hetero atoms contained
in the aromatic heterocyclic ring represented by Q32 are not
especially restricted, but an aromatic heterocyclic ring containing
nitrogen, oxygen, sulfur, selenium, silicon, germanium or phosphorus is
preferred, nitrogen, oxygen or sulfur is more preferred, nitrogen or
oxygen is still more preferred, and nitrogen is especially preferred. The
number of hetero atoms contained in one aromatic heterocyclic ring is not
especially restricted, but the number of from 1 to 3 is preferred.

[0089]The specific examples of the rings of the aryl group or aromatic
heterocyclic group represented by Q32 include a benzene ring, a
pyridine ring, a pyrazine ring, a pyrimidine ring, a triazine ring, a
pyridazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a
triazole ring, an oxazole ring, an oxadiazole ring, a thiazole ring, a
thiadiazole ring, a furan ring, a thiophene ring, a selenophene ring, a
silol ring, a germole ring, and a phosphole ring.

[0090]The aryl group or aromatic heterocyclic group formed of Q32 may
have a substituent, and substituent group A described above is applicable
to the substituents.

[0091]The rings of the aryl group or aromatic heterocyclic group
represented by Q32 include preferably a benzene ring, a pyridine
ring, a pyrazine ring, a pyrimidine ring, a triazine ring, a pyridazine
ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole
ring, an oxazole ring, an oxadiazole ring, a thiazole ring, a thiadiazole
ring, a furan ring, a thiophene ring, a selenophene ring, a silol ring, a
germole ring, and a phosphole ring, more preferably a benzene ring, a
pyridine ring, a pyrazine ring, a pyrrole ring, a pyrazole ring, an
imidazole ring, an oxazole ring, a thiazole ring, and a thiadiazole ring,
still more preferably a benzene ring, a pyridine ring, a pyrazine ring, a
pyrazole ring, an imidazole ring, and a thiadiazole ring, and especially
preferably a benzene ring, a pyridine ring and a pyrazine ring.

##STR00023##

[0092]In formula (IV), R41 represents a hydrogen atom or a
substituent. At least one of R41 represents an aryl group or an
aromatic heterocyclic group. When there are present a plurality of
partial structures represented by the following formula (IV-a), each
partial structure (IV-a) may be the same with or different from every
other (IV-a). Q41 represents a monocyclic aryl group or an aromatic
heterocyclic group. Each Q41 may be the same with or different from
every other Q41. R42 represents an alkyl group. Each R42
may be the same with or different from every other R42. Each of n, m
and l represents an integer of from 0 to 4, provided that n is an integer
of 1 or more, n+m is an integer of 2 or more, and n+m+l is 4.

##STR00024##

[0093]In formula (IV), R41, R42, Q41, n, m and l
respectively have the same meanings as R21, R22, Q21, n, m
and l in formula (II), and preferred ranges are also the same.

[0094]For maintaining high excitation triplet energy level, the compound
represented by formula (IV) is more preferably a compound represented by
the following formula (IV-b).

##STR00025##

[0095]In formula (IV-b), R41 represents a hydrogen atom or a
substituent. At least one of R41 represents an aryl group or an
aromatic heterocyclic group. When there are present a plurality of
partial structures represented by the following formula (IV-b)', each
partial structure (IV-b)' may be the same with or different from every
other (IV-b)'. Q41 represents a monocyclic aryl group or an aromatic
heterocyclic group. Each Q41 may be the same with or different from
every other Q41. Q42 represents an aryl group or an aromatic
heterocyclic group. R42 represents an alkyl group. Each R42 may
be the same with or different from every other R42. Each of n, m and
l represents an integer of from 0 to 4, provided that n is an integer of
1 or more, n+m is an integer of 2 or more, and n+m+l is 4.

##STR00026##

[0096]Formula (IV-b) is described below. R41, R42, Q41, n,
m and l respectively have the same meanings as R21, R22,
Q21, n, m and l in formula (II), and preferred ranges are also the
same, Q42 has the same meaning as Q32 in formula (III-b), and a
preferred range is also the same.

##STR00027##

[0097]In formula (V), R51 represents a hydrogen atom or a
substituent. At least one of R51 represents an aryl group or an
aromatic heterocyclic group. When there are present a plurality of
partial structures represented by the following formula (V-a), each
partial structure (V-a) may be the same with or different from every
other (V-a). Q51 represents a monocyclic aryl group or an aromatic
heterocyclic group. Each Q51 may be the same with or different from
every other Q51. R52 represents an alkyl group. Each R52
may be the same with or different from every other R52. Each of n, m
and l represents an integer of from 0 to 4, provided that n is an integer
of 1 or more, n+m is an integer of 2 or more, and n+m+l is 4.

##STR00028##

[0098]Formula (V) is described below. R51, R52, QS, n, m and l
respectively have the same meanings as R21, R22, Q21, n, m
and l in formula (II), and preferred ranges are also the same.

[0099]For maintaining high excitation triplet energy level, the compound
represented by formula (V) is more preferably a compound represented by
the following formula (V-b).

##STR00029##

[0100]In formula (V-b), R51 represents a hydrogen atom or a
substituent. At least one of R51 represents an aryl group or an
aromatic heterocyclic group. When there are present a plurality of
partial structures represented by the following formula (V-b)', each
partial structure (V-b)' may be the same with or different from every
other (V-b)'. Q51 represents a monocyclic aryl group or an aromatic
heterocyclic group. Each Q51 may be the same with or different from
every other Q51. Q52 represents an aryl group or an aromatic
heterocyclic group. R52 represents an alkyl group. Each R52 may
be the same with or different from every other R52. Each of n, m and
l represents an integer of from 0 to 4, provided that n is an integer of
1 or more, n+m is an integer of 2 or more, and n+m+l is 4.

##STR00030##

[0101]Formula (V-b) is described below. R51, R52, Q51, n, m
and l respectively have the same meanings as R21, R22,
Q21, n, m and l in formula (II), and preferred ranges are also the
same. Q52 has the same meaning as Q32 in formula (III-b), and a
preferred range is also the same.

[0102]The compound represented by formula (I) of the invention may be a
low molecular weight compound, or may be a polymer compound having a
residue structure linking to the polymer main chain (preferably having a
mass average molecular weight of from 1,000 to 5,000,000, more preferably
from 5,000 to 2,000,000, and still more preferably from 10,000 to
1,000,000), or may be a polymer compound having the structure of the
compound represented by formula (I) in the main chain (preferably having
a mass average molecular weight of from 1,000 to 5,000,000, more
preferably from 5,000 to 2,000,000, and still more preferably from 10,000
to 1,000,000). In the case of a polymer compound, it may be a
homopolymer, or may be a copolymer with other polymer, and in the case of
a copolymer, it may be a random copolymer, or may be a block copolymer.
Furthers in the case of a copolymer, at least one of a compound having a
light emitting function and a compound having a charge transporting may
be contained in the polymer.

[0103]The specific examples of the compounds represented by formula (I),
(II), (III), (IV) or (V) are shown below, but the invention is not
restricted to these compounds. (Incidentally in the present
specification, Ph means a phenyl group, and tBu means a tertiary
butyl group.)

[0104]The compounds represented by any of formulae (I) to (V) of the
invention can be synthesized according to various well-known synthesizing
methods.

[0105]The specific synthesizing prescriptions are described in the
Examples below.

[0106]Considering the driving durability of the device, the glass
transition temperature (Tg) of the compound of the invention is
preferably 130° C. or more and 450° C. or less, more
preferably 135° C. or more and 450° C. or less, still more
preferably 140° C. or more and 450° C. or less, especially
preferably 150° C. or more and 450° C. or less, and most
preferably 160° C. or more and 450° C. or less.

[0107]Here, Tg can be confirmed by thermal measurement such as
differential scanning calorimetry (DSC) and differential thermal analysis
(DTA), X-ray diffraction (XRD), and observation with a polarization
microscope. Measurement of Tg by differential scanning calorimetry (DSC)
is especially preferred.

[0108]When the device of the invention is a luminescence device utilizing
phosphorescence, the lowest excitation triplet energy (T1 energy) of
the compound of the invention is preferably 64 kcal/mol (272.35 kJ/mol)
or more and 95 kcal/mol (398.05 kJ/mol) or less, more preferably 67
kcal/mol (280.73 kJ/mol) or more and 95 kcal/mol (398.05 kJ/mol) or less,
and still more preferably 69 kcal/mol (289.11 kJ/mol) or more and 95
kcal/mol (398.05 kJ/mol) or less.

[0109]Here, T1 level can be found by measuring the spectrum of
phosphorescence of the film of a material, and from the short wave end of
the spectrum of phosphorescence. For example, T1 level of
Exemplified Compound 91 is 64 kcal/mol, and T1 level of Exemplified
Compound 116 is 74 kcal/mol.

Organic Electroluminescence Device:

[0110]It is preferred for the organic electroluminescence device to have
at least one electron transporting layer between the light-emitting layer
and the cathode, wherein the at least one electron transporting layer
contains the compound represented by formulae (I)

[0111]The organic electroluminescence device in the invention comprises a
substrate having thereon the cathode and the anode and an organic layer
including a light-emitting layer between the electrodes. It is preferred
that at least one electrode of the cathode and the anode is transparent
from the properties of the luminescence device.

[0112]As the form of lamination of the organic layers in the invention, an
embodiment of lamination of a hole-transporting layer, a light-emitting
layer and an electron-transporting layer from the anode side is
preferred. Further, a hole-injecting layer is provided between the
hole-transporting layer and the anode, and/or an electron-transporting
intermediate layer is provided between the light-emitting layer and the
electron-transporting layer. In addition, it is also possible to provide
a hole-transporting intermediate layer between the light-emitting layer
and the hole-transporting layer and an electron-injecting layer between
the cathode and the electron-transporting layer

[0113]Incidentally, each of these layers may consist of a plurality of
layers.

[0114]Each layer constituting the organic layers can be preferably formed
by any of dry film-forming methods such as a vacuum deposition method or
a sputtering method, a transfer method, a printing method, a coating
method, an ink jet method, and a spraying method.

[0115]The elements constituting the luminescence device of the invention
will be described in detail below.

Substrate:

[0116]The substrate for use in the invention is preferably a substrate
that does not scatter or attenuate the light emitted from the organic
layers. The specific examples of the materials of the substrate include
inorganic materials, e.g., yttria stabilized zirconia (YSZ), glass, etc.,
and organic materials, such as polyester, e.g., polyethylene
terephthalate, polybutylene phthalate, polyethylene naphthalate, etc.,
polystyrene, polycarbonate, polyether sulfone, polyallylate, polyimide,
polycycloolefin, norbornene resin, poly(chlorotrifluoroethylene), etc.

[0117]When glass is used as the substrate, non-alkali glass is preferably
used as the material for reducing elution of ions from the glass.
Further, when soda lime glass is used, it is preferred to provide a
barrier coat such as silica. In the case of organic materials, materials
excellent in heat resistance, dimensional stability, solvent resistance,
electrical insulating properties and processability are preferably used.

[0118]The shape, structure and size of the substrate are not especially
restricted, and these can be arbitrarily selected in accordance with the
intended use and purpose of the luminescent device. In general, the
substrate is preferably plate-shaped. The structure of the substrate may
be a single layer structure or may be a lamination structure, and may
consist of a single member or may be formed of two or more members.

[0119]The substrate may be colorless and transparent, or may be colored
and transparent, but from the point of not scattering or attenuating the
light emitted from the organic light-emitting layer, a colorless and
transparent substrate is preferably used.

[0120]The substrate can be provided with a moisture permeation preventing
layer (a gas barrier layer) on the front surface or rear surface.

[0121]As the materials of the moisture permeation-preventing layer (the
gas barrier layer), inorganic materials such as silicon nitride and
silicon oxide are preferably used. The moisture permeation-preventing
layer (the gas barrier layer) can be formed, for example, by a high
frequency sputtering method.

[0122]When a thermoplastic substrate is used, if necessary, a hard coat
layer and an undercoat layer may further be provided.

Anode:

[0123]The anode is generally sufficient to have the function of the
electrode to supply holes to an organic layer. The shape, structure and
size of the anode are not especially restricted, and these can be
arbitrarily selected from known materials of electrode in accordance with
the intended use and purpose of the luminescent device. The anode is
generally provided as the transparent anode.

[0125]The anode can be formed on the substrate in accordance with various
methods arbitrarily selected from, for example, wet methods, e.g., a
printing method, a coating method, etc., physical methods, e.g., a vacuum
deposition method, a sputtering method, an ion plating method, etc., and
chemical methods, e.g., a CVD method, a plasma CVD method, etc., taking
the suitability with the material to be used in the anode into
consideration. For example, in the case of selecting ITO as the material
of the anode, the anode can be formed according to a direct current or
high frequency sputtering method, a vacuum deposition method, an ion
plating method, etc.

[0126]In the organic electroluminescent device in the invention, the
position of the anode to be formed is not especially restricted and can
be formed anywhere in accordance with the intended use and purpose of the
luminescent device, but preferably provided on the substrate. In this
case, the anode may be formed on the entire surface of one side of the
substrate, or may be formed at a part.

[0127]As patterning in forming the anode, patterning may be performed by
chemical etching such as by photo-lithography, may be carried out by
physical etching by laser and the like, may be performed by vacuum
deposition or sputtering on a superposed mask, or a lift-off method and a
printing method may be used.

[0128]The thickness of the anode can be optionally selected in accordance
with the materials of the anode, so that it cannot be regulated
unconditionally, but the thickness is generally from 10 nm to 50 μm or
so, and is preferably from 50 nm to 20 μm.

[0129]The value of resistance of the anode is preferably
103Ω/quadrature or less, and more preferably
102Ω/quadrature or less. In the case where the anode is
transparent, it may be colorless and transparent, or may be colored and
transparent. For collecting emission from the transparent anode side, the
transmittance is preferably 60% or more, and more preferably 70% or more.

[0130]In connection with transparent anodes, description is found in
Yutaka Sawada supervised, Tomei Denkyoku-Maku no Shintenkai (New
Development in Transparent Conductive Films), CMC Publishing Co., Ltd.
(1999), and the description therein can be applied to the invention. In
the case of using a plastic substrate low in heat resistance, a
transparent anode film formed with ITO or IZO at a low temperature of
150° C. or less is preferred.

Cathode:

[0131]The cathode is generally sufficient to have the function of the
electrode to inject electrons to organic layers. The shape, structure and
size of the cathode are not especially restricted, and these can be
arbitrarily selected from known materials of electrode in accordance with
the intended use and purpose of the luminescent device.

[0132]As the materials to constitute the cathode, for example, metals,
alloys, metallic oxides, electrically conductive compounds, and mixtures
of these materials are exemplified. The specific examples of the
materials of cathode include alkali metals (e.g., Li, Na, K, Cs, etc.),
alkaline earth metals (e.g., Mg, Ca, etc.), gold, silver, lead, aluminum,
sodium-potassium alloy, lithium-aluminum alloy, magnesium-silver alloy,
indium, rare earth metals, e.g., ytterbium, etc. These materials may be
used by one kind alone, but from the viewpoint of the compatibility of
stability and an electron injecting property, two or more kinds of
materials can be preferably used in combination.

[0133]As the materials constituting the cathode, alkali metals and
alkaline earth metals are preferred of these materials in the point of an
electron injecting property, and materials mainly comprising aluminum are
preferred for their excellent preservation stability.

[0135]The materials of the cathode are disclosed in detail in JP-A-2-15595
and IP-A-5-121172, and the materials described in these patents can also
be used in the invention.

[0136]The cathode can be formed by known methods with no particular
restriction. For example, the cathode can be formed according to wet
methods, e.g., a printing method, a coating method, etc., physical
methods, e.g., a vacuum deposition method, a sputtering method, an ion
plating method, etc., and chemical methods, e.g., a CVD method, a plasma
CVD method, etc., taking the suitability with the material constituting
the cathode into consideration. For example, in the case of selecting
metals as the materials of the cathode, the cathode can be formed with
one or two or more kinds of the materials at the same time or in order by
a sputtering method, etc.

[0137]Patterning in forming the cathode may be performed by chemical
etching such as a method by photo-lithography, may be carried out by
physical etching such as a method by laser, may be performed by vacuum
deposition or sputtering on a superposed mask, or a lift-off method and a
printing method may be used.

[0138]The position of the cathode to be formed is not especially
restricted and can be formed anywhere in the invention. The cathode may
be formed on the entire surface of the organic layer, or may be formed at
a part.

[0139]A dielectric layer comprising fluoride or oxide of alkali metal or
alkaline earth metal may be inserted between the cathode and the organic
layer in a thickness of from 0.1 to 5 nm. The dielectric layer can be
regarded as a kind of an electron-injecting layer. The dielectric layer
can be formed, for example, according to a vacuum deposition method, a
sputtering method, an ion plating method, etc.

[0140]The thickness of the cathode can be optionally selected in
accordance with the materials of the cathode, so that it cannot be
regulated unconditionally, but the thickness is generally from 10 nm to 5
μm or so, and is preferably from 50 nm to 1 μm.

[0141]The cathode may be transparent or opaque. The transparent cathode
can be formed by forming a film of the material of the cathode in a
thickness of from 1 to 10 nm, and further laminating transparent
conductive materials such as ITO and Organic Layers:

[0142]Organic layers in the invention will be described below.

[0143]The organic electroluminescence device in the invention has at least
one organic layer including a light-emitting layer between a pair of
electrodes, and as the organic layers other than the light-emitting
layer, a hole transporting layer, an electron transporting layer, a
charge blocking layer, a hole injecting layer, and an electron injecting
layer are exemplified, as described above.

Forming Method of Organic Layers:

[0144]In the organic electroluminescence device of the invention, each
layer constituting the organic layers can be suitably formed by any of
dry film-forming methods such as a vacuum deposition method, a sputtering
method, etc., a transfer method, and a printing method, etc.

Organic Light-Emitting Layer:

[0145]The light-emitting layer is a layer having functions to receive, at
the time of electric field application, holes from the anode, hole
injecting layer or hole transporting layer, and to receive electrons from
the cathode, electron injecting layer or electron transporting layer, and
offer the field of recombination of holes and electrons to emit light.
The light-emitting layer may be a single layer, or may comprise two or
more layers, and each layer may emit light in different luminescent
color.

[0146]The light-emitting layer in the invention may consist of
light-emitting materials alone, or may comprise a mixed layer of a host
material and a light-emitting material. As the host material, the
compound represented by formula (I) of the invention is preferred, but
compounds other than the compound according to the invention may be used
in combination or alone. The details will be described in the item of
"Host Materials" later. Further, a material not having a
charge-transporting property and not emitting light may be contained in
the light-emitting layer.

Light-Emitting Materials:

[0147]The light-emitting material may be a phosphorescent material or a
fluorescent material, and one or two or more kinds may be used.

[0148]The light-emitting layer in the invention can contain two or more
light-emitting materials for the purpose of improving color purity and
widening light emission wavelength region.

[0149]The at least one light-emitting material may be a phosphorescent
material.

[0151]As the examples of phosphorescent materials that can be used in the
invention, complexes containing a transition metal atom or a lanthanoid
atom are exemplified.

[0152]For example, the transition metal atoms are not especially
restricted, but preferably ruthenium, rhodium, palladium, tungsten,
rhenium, osmium, iridium, and platinum are exemplified, more preferably
rhenium, iridium and platinum, and still more preferably iridium and
platinum are exemplified.

[0155]As the specific examples of ligands, halogen ligands (preferably a
chlorine ligand), aromatic carbocyclic ligands (preferably having from 5
to 30 carbon atoms, more preferably from 6 to 30 carbon atoms, still more
preferably from 6 to 20 carbon atoms, and especially preferably from 6 to
12 carbon atoms, e.g., a cyclopentadienyl anion, a benzene anion, a
naphthyl anion, etc.), nitrogen-containing heterocyclic ligands
(preferably having from 5 to 30 carbon atoms, more preferably from 6 to
30 carbon atoms, still more preferably from 6 to 20 carbon atoms, and
especially preferably from 6 to 12 carbon atoms, e.g., pyrazolylpyridine,
pyrrolylpyridine, imidazolylpyridine, triazolylpyridine,
phenylisoquinoline, picolinic acid, phenylpyridine, benzoquinoline,
quinolinol, bipyridyl, phenanthroline, etc.), diketone ligands (e.g.,
acetylacetone, etc.), carboxylic acid ligands (preferably having from 2
to 30 carbon atoms, more preferably from 2 to 20 carbon atoms, and still
more preferably from 2 to 16 carbon atoms, e.g., an acetic acid ligand,
etc.), alcoholate ligands (preferably having from 1 to 30 carbon atoms,
more preferably from 1 to 20 carbon atoms, and still more preferably from
6 to 20 carbon atoms, e.g., a phenolate ligand, etc.), silyloxy ligands
(preferably having from 3 to 40 carbon atoms, more preferably from 3 to
30 carbon atoms, and still more preferably from 3 to 20 carbon atoms,
e.g., a trimethylsilyloxy ligand, a dimethyl-tert-butysilyloxy ligand, a
triphenylsilyloxy ligand, etc.), carbon monoxide ligands, isonitrile
ligands, cyano ligands, phosphorus ligands (preferably having from 3 to
40 carbon atoms, more preferably from 3 to 30 carbon atoms, still more
preferably from 3 to 20 carbon atoms, and especially preferably from 6 to
20 carbon atoms, e.g., a triphenylphosphine ligand, etc.), thiolate
ligands (preferably from 1 to 30 carbon atoms, more preferably from 1 to
20 carbon atoms, and still more preferably from 6 to 20 carbon atoms,
e.g., a phenylthiolate ligand, etc.), phosphine oxide ligands (preferably
having from 3 to 30 carbon atoms, more preferably from 8 to 30 carbon
atoms, and still more preferably from 18 to 30 carbon atoms, e.g., a
triphenylphosphine oxide ligand, etc.) are preferably exemplified, and
more preferably nitrogen-containing heterocyclic ligands are exemplified.

[0156]These complexes may have one transition metal atom in a compound, or
they may be what are called polynuclear complexes having two or more
transition metal atoms. They may contain dissimilar metal atoms at the
same time.

[0157]As the phosphorescent materials, iridium complexes and platinum
complexes are preferred, in particular, platinum complexes having a
tetradentate ligand and platinum complexes having fluorine-substituted
phenylpyridine as the ligand are preferred, and platinum complexes having
a tetradentate ligand are most preferred.

[0159]As phosphorescent materials, iridium complexes, platinum complexes
and rhenium complexes having at least one coordination manner of a
metal-carbon bond, a metal-nitrogen bond, a metal-oxygen bond, and a
metal-sulfur bond are preferred. Further, from the viewpoints of luminous
efficiency, driving durability and chromaticity, an iridium complex, a
platinum complex and a rhenium complex containing a tridentate or higher
multidentate ligand are especially preferred. A platinum complex having a
tridentate or tetradentate ligand is most preferred.

[0160]As the platinum complex, a platinum complex represented by the
following formula (C-1) is preferred.

##STR00069##

[0161]In formula (C-1), each of Q1, Q2, Q3 and Q4
independently represents a ligand to coordinate to Pt; and each of
L1, L2 and L3 independently represents a single bond or a
divalent liking group.

[0162]The platinum complex represented by formula (C-1) will be explained
below. Each of Q1, Q2, Q3 and Q4 independently
represents a ligand to coordinate to Pt. At this time, bonding of
Q1, Q2, Q1 and Q4 to Pt may be any of a covalent
bond, an ionic bond, and a coordinate bond. The atoms in Q1,
Q2, Q3 and Q4 to bond to Pt are preferably a carbon atom,
a nitrogen atom, an oxygen atom, a sulfur atom and a phosphorus atom, and
it is preferred that at least one of the atoms in Q1, Q2,
Q3 and Q4 to bond to Pt is a carbon atom, and it is more
preferred that two of these atoms are carbon atoms.

[0163]Q1, Q2, Q3 and Q4 to bond to Pt via a carbon
atom may be an anionic ligand or a neutral ligand. As the anionic
ligands, a vinyl ligand, an aromatic hydrocarbon ring ligand (e.g., a
benzene ligand, a naphthalene ligand, an anthracene ligand, a
phenanthrene ligand, etc.), a heterocyclic ligand (e.g., a furan ligand,
a thiophene ligand, a pyridine ligand, a pyrazine ligand, a pyrimidine
ligand, a pyridazine ligand, a triazine ligand, a thiazole ligand, an
oxazole ligand, a pyrrole ligand, an imidazole ligand, a pyrazole ligand,
a triazole ligand, and condensed ring products containing these ligands
(e.g., a quinoline ligand, a benzothiazole ligand, etc.)) are
exemplified. As the neutral ligand, a carbene ligand is exemplified.

[0164]Q1, Q2, Q3 and Q4 to bond to Pt via a nitrogen
atom may be a neutral ligand or an anionic ligand. As the neutral
ligands, a nitrogen-containing aromatic heterocyclic ligand (a pyridine
ligand, a pyrazine ligand, a pyrimidine ligand, a pyridazine ligand, a
triazine ligand, an imidazole ligand, a pyrazole ligand, a triazole
ligand, an oxazole ligand, a thiazole ligand, and condensed ring products
containing these ligands (e.g., a quinoline ligand, a benzimidazole
ligand, etc.)), an amine ligand, a nitrile ligand, and an imine ligand
are exemplified. As the anionic ligands, an amino ligand, an imino
ligand, a nitrogen-containing aromatic heterocyclic ligand (e.g., a
pyrrole ligand, an imidazole ligand, a triazole ligand, and condensed
ring products containing these ligands (e.g., an indole ligand, a
benzimidazole ligand, etc.)) are exemplified.

[0165]Q1, Q2, Q3 and Q4 to bond to Pt via an oxygen
atom may be a neutral ligand or an anionic ligand. As the neutral
ligands, an ether ligand, a ketone ligand, an ester ligand, an amido
ligand, an oxygen-containing heterocyclic ligand (e.g., a furan ligand,
an oxazole ligand, and condensed ring products containing these ligands
(e.g., a benzoxazole ligand, etc.)) are exemplified. As the anionic
ligands, an alkoxy ligand, an aryloxy ligand, a hetero-aryloxy ligand, an
acyloxy ligand, a silyloxy ligand, etc., are exemplified.

[0166]Q1, Q2, Q3 and Q4 to bond to Pt via a sulfur
atom may be a neutral ligand or an anionic ligand. As the neutral
ligands, a thioether ligand, a thioketone ligand, a thioester ligand, a
thioamide ligand, a sulfur-containing heterocyclic ligand (e.g., a
thiophene ligand, a thiazole ligand, and condensed ring products
containing these ligands (e.g., a benzothiazole ligand, etc.)) are
exemplified. As the anionic ligands, an alkylmercapto ligand, an
arylmercapto ligand, a hetero-arylmercapto ligand, etc., are exemplified.

[0167]Q1, Q2, Q3 and Q4 to bond to Pt via a phosphorus
atom may be a neutral ligand or an anionic ligand. As the neutral
ligands, a phosphine ligand, a phosphoric ester ligand, a phosphorous
ester ligand, a phosphorus-containing ligand (e.g., a phosphinine ligand,
etc.) are exemplified. As the anionic ligands, a phosphino ligand, a
phosphinyl ligand, a phosphoryl ligand are exemplified.

[0168]Each of the groups represented by Q1, Q2, Q3 and
Q4 may have a substituent, and as the substituents, those
exemplified above as substituent group A can be arbitrarily applied. In
addition, substituents may be linked to each other (when Q3 and
Q4 are linked, the Pt complex is a Pt complex of a cyclic
tetradentate ligand).

[0169]The groups represented by Q1, Q2, Q3 and Q4 are
preferably an aromatic hydrocarbon ring ligand to bond to Pt via a carbon
atom, an aromatic heterocyclic ligand to bond to Pt via a carbon atom, a
nitrogen-containing aromatic heterocyclic ligand to bond to Pt via a
nitrogen atom, an acyloxy ligand, an alkyloxy ligand, an aryloxy ligand,
a hetero-aryloxy ligand, and a silyloxy ligand, more preferably an
aromatic hydrocarbon ring ligand to bond to Pt via a carbon atom, an
aromatic heterocyclic ligand to bond to Pt via a carbon atom, a
nitrogen-containing aromatic heterocyclic ligand to bond to Pt via a
nitrogen atom, an acyloxy ligand, and an aryloxy ligand, and still more
preferably an aromatic hydrocarbon ring ligand to bond to Pt via a carbon
atom, an aromatic heterocyclic ligand to bond to Pt via a carbon atom, a
nitrogen-containing aromatic heterocyclic ligand to bond to Pt via a
nitrogen atom, and an acyloxy ligand.

[0170]Each of L1, L2 and L3 represents a single bond or a
divalent linking group. As the divalent linking groups represented by
L1, L2 and L3, an alkylene group (e.g., methylene,
ethylene, propylene, etc.), an arylene group (e.g., phenylene,
naphthalenediyl), a hetero-arylene group (e.g., pyridinediyl,
thiophenediyl, etc.), an imino group (--NR--) (e.g., a phenylimino group,
etc.), an oxy group (--O--), a thio group (--S--), a phosphinidene group
(--PR--) (e.g., a phenylphosphinidene group, etc.), a silylene group
(--SiRR'--) (e.g., a dimethylsilylene group, a diphenylsilylene group,
etc.), and groups obtained by combining these groups are exemplified.
These linking groups may further have a substituent.

[0171]Each of L1, L2 and L3 preferably represents a single
bond, an alkylene group, an arylene group, a hetero-arylene group, an
imino group, an oxy group, a thio group, or a silylene group, more
preferably a single bond, an alkylene group, an arylene group, or an
imino group, still more preferably a single bond, an alkylene group, or
an arylene group, still further preferably a single bond, a methylene
group, or a phenylene group, still yet more preferably a single bond, a
di-substituted methylene group, still yet further preferably a single
bond, a dimethylmethylene group, a diethylmethylene group, a
diisobutylmethylene group, a dibenzylmethylene group, an ethylmethylene
group, a methylpropylmethylene group, an isobutylmethylmethylene group, a
diphenylmethylene group, a methylphenylmethylene group, a cyclohexanediyl
group, a cyclopentanediyl group, a fluorenediyl group, or a
fluoromethylmethylene group, and especially preferably represents a
single bond, a dimethylmethylene groups a diphenylmethylene group, or a
cyclohexanediyl group.

[0172]The platinum complex represented by formula (C-1) is more preferably
represented by the following formula (C-2).

##STR00070##

[0173]In formula (C-2), L1 represents a single bond or a divalent
linking group; each of A1, A2, A3, A4, A5 and
A6 independently represents C--R or N; R represents a hydrogen atom
or a substituent; each of X1 and X2 represents C or N; and each
of Z1 and Z2 represents a 5- or 6-membered aromatic ring or an
aromatic heterocyclic ring formed together with X--C in the formula,

[0174]Formula (C-2) will be described below. L1 has the same
definition as in formula (C-1) and the preferred range is also the same.
Each of A1, A2, A3, A4, A5 and A6
independently represents C--R or N. R represents a hydrogen atom or a
substituent. As the substituents represented by R, those exemplified
above as substituent group A can be applied.

[0175]Each of A1, A2, A3, A4, A5 and A6
preferably represents C--R, and R may be linked to each other to form a
ring. When each of A1, A2, A3, A4, A5 and
A6 represents C--R, R represented by A2 and A5 is
preferably a hydrogen atom, an alkyl group, an aryl group, an amino
group, an alkoxy group, an aryloxy group, a fluorine group, or a cyano
group, more preferably a hydrogen atom, an amino group, an alkoxy group,
an aryloxy group, or a fluorine group, and especially preferably a
hydrogen atom or a fluorine group. R represented by A1, A3,
A4 and A6 is preferably a hydrogen atom, an alkyl group, an
aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine
group, or a cyano group, more preferably a hydrogen atom, an amino group,
an alkoxy group, an aryloxy group, or a fluorine group, and especially
preferably a hydrogen atom. Each of X1 and X2 represents C or
N. Z1 represents a 5- or 6-membered aromatic hydrocarbon ring or an
aromatic heterocyclic ring formed together with X1--C in the
formula. Z2 represents a 5- or 6-membered aromatic hydrocarbon ring
or an aromatic heterocyclic ring formed together with X2--C in the
formula. As the aromatic hydrocarbon rings or the aromatic heterocyclic
rings represented by Z1 and Z2, a benzene ring, a naphthalene
ring, an anthracene ring, a pyrene ring, a phenanthrene ring, a perylene
ring, a pyridine ring, a quinoline ring, an isoquinoline ring, a
phenanthridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine
ring, a triazine ring, a cinnoline ring, an acridine ring, a phthalazine
ring, a quinazoline ring, a quinoxaline ring, a naphthyridine ring, a
pteridine ring, a pyrrole ring, a pyrazole ring, a triazole ring, an
indole ring, a carbazole ring, an indazole ring, a benzimidazole ring, an
oxazole ring, a thiazole ring, an oxadiazole ring, a thiadiazole ring, a
benzoxazole ring, a benzothiazole ring, an imidazopyridine ring, a
thiophene ring, a benzothiophene ring, a furan ring, a benzofuran ring, a
phosphor ring, a phosphinine ring, and a silol ring are exemplified.
Z1 and Z2 may have a substituent, and as the substituents,
those exemplified above as substituent group A can be applied. Further,
Z1 and Z2 may form a condensed ring with other rings.

[0176]Each of Z1 and Z2 preferably represents a benzene ring, a
naphthalene ring, a pyrazole ring, an imidazole ring, a triazole ring, a
pyridine ring, an indole ring or a thiophene ring, and more preferably a
benzene ring, a pyrazole ring or a pyridine ring.

[0177]The platinum complex represented by formula (C-2) is more preferably
represented by the following formula (C-3),

##STR00071##

[0178]In formula (C-3), each of A1 to A13 independently
represents C--R or N. R represents a hydrogen atom or a substituent.
L1 represents a single bond or a divalent linking group.

[0179]As the specific examples of the light-emitting materials, for
example, the following are exemplified, but the invention is not
restricted thereto.

[0180]The light-emitting material is generally contained in the
light-emitting layer in an amount of from 0.1 to 50 mass % based on the
mass of all the compounds forming the light-emitting layer, preferably
from 0.2 to 50 mass % in view of durability and external quantum
efficiency, and more preferably from 0.5 to 40 mass %.

[0181]The phosphorescent material is preferably contained in the
light-emitting layer in an amount of from 0.1 to 40 mass %, and more
preferably from 0.5 to 20 mass %.

[0182]The thickness of the light-emitting layer is not especially
restricted, but generally preferably the thickness is from 1 to 500 nm,
more preferably from 5 to 200 nm, and still more preferably from 10 to
100 nm.

Host Materials:

[0183]As host materials contained in the light-emitting layer in the
invention, besides the compounds of the invention, for example, compounds
having a carbazole structure, compounds having a diarylamine structure,
compounds having a pyridine structure, compounds having a pyrazine
structure, compounds having a triazine structure, and compounds having an
arylsilane structure, and materials exemplified in the items of the
later-described hole injecting layer, hole transporting layer, electron
injecting layer, and electron transporting layer are exemplified.

[0184]The host materials are preferably charge-transporting materials. The
host material may be used by one kind alone or two or more kinds may be
used, and, for example, the constitution of the mixture of an electron
transporting host material and a hole transporting host material is
exemplified.

[0185]The content of the host compound in the invention is not especially
restricted, but from the aspects of luminous efficiency and driving
voltage, the content of the host compound is preferably 5 mass % or more
and 99.5 mass % or less based on the mass of all the compounds forming
the light-emitting layer, and more preferably 15 mass % or more and 95
mass % or less.

[0187]The hole injecting layer or hole transporting layer of the organic
EL device in the invention can contain an electron accepting dopant. As
the electron accepting dopants to be introduced to the hole injecting
layer or hole transporting layer, either inorganic compounds or organic
compounds can be used so long as they are electron-acceptive and have a
property capable of oxidizing organic compounds.

[0188]Specifically, the examples of the inorganic compounds include metal
halides, such as ferric chloride, aluminum chloride, gallium chloride,
indium chloride, and antimony pentachloride, and metallic oxides, such as
vanadium pentoxide and molybdenum trioxide.

[0189]In the case of organic compounds, compounds having a nitro group,
halogen, a cyano group or a trifluoromethyl group as the substituent,
quinone compounds, acid anhydride compounds and Fullerene can be
preferably used.

[0192]These electron accepting dopants may be used by one kind alone, or
two or more dopants may be used. The amount to be used of the electron
accepting dopants differs according to the kind of the material, but the
amount is preferably from 0.01 to 50 mass % on the basis of the material
of the hole transporting layer, more preferably from 0.05 to 20 mass %,
and especially preferably from 0.1 to 10 mass %.

[0193]The thickness of the hole-injecting layer and hole transporting
layer is each preferably 500 nm or less in view of lowering driving
voltage.

[0194]The thickness of the hole-transporting layer is preferably from 1 to
500 nm, more preferably from 5 to 200 nm, and still more preferably from
10 to 100 nm. The thickness of the hole-injecting layer is preferably
from 0.1 to 200 nm, more preferably from 0.5 to 100 nm, and still more
preferably from 1 to 100 nm.

[0195]The hole-injecting layer and the hole-transporting layer may have a
single layer structure comprising one kind or two or more kinds of the
above materials, or may be a multilayer structure comprising a plurality
of layers having the same composition or different compositions.

[0197]The electron-injecting layer and the electron-transporting layer of
the organic EL device of the invention can contain an electron donating
dopant. The electron donating dopants to be introduced to the
electron-injecting layer and the electron-transporting layer are
sufficient to be electron donating and have a property capable of
reducing organic compounds, and alkali metals such as Li, alkaline earth
metals such as Mg, transition metals containing rare earth metals, and
reductive organic compounds are preferably used. As the metals, metals
having a work function of 4.2 eV or less can be preferably used, and
specifically Li, Na, K, Be, Mg, Ca, Sr, Ba, Y, Cs, La, Sm, Gd, and Yb are
exemplified. As the reductive organic compounds, e.g.,
nitrogen-containing compounds, sulfur-containing compounds and
phosphorus-containing compounds are exemplified.

[0198]In addition to the above, materials disclosed in JP-A-6-212153,
JP-A-2000-196140, JP-A-2003-68468, JP-A-2003-229278 and JP-A-2004-342614
can be used.

[0199]These electron-donating dopants may be used by one kind alone, or
two or more kinds of dopants may be used. The amount to be used of the
electron-donating dopants differs by the kinds of materials, but the
amount is preferably from 0.1 to 99 mass % on the basis of the electron
transporting layer material, more preferably from 1.0 to 80 mass %, and
especially preferably from 2.0 to 70 mass %.

[0200]The thickness of the electron injecting layer and the electron
transporting layer is preferably 500 nm or less from the point of
lowering the driving voltage.

[0201]The thickness of the electron transporting layer is preferably from
1 to 500 nm, more preferably from 5 to 200 nm, and still more preferably
from 10 to 100 nm. The thickness of the electron injecting layer is
preferably from 0.1 to 200 nm, more preferably from 0.2 to 100 nm, and
still more preferably from 0.5 to 50 nm.

[0202]The electron injecting layer and the electron transporting layer may
have a single layer structure comprising one kind or two or more kinds of
the above materials, or may be a multilayer structure comprising a
plurality of layers having the same composition or different
compositions.

Hole-Blocking Layer:

[0203]The hole-blocking layer is a layer having a function of preventing
the holes transported from the anode side to the light-emitting layer
from passing through to the cathode side. In the invention, a
hole-blocking layer can be provided as an organic layer contiguous to the
light-emitting layer on the cathode side.

[0204]As the examples of the compounds constituting the hole-blocking
layer, aluminum complexes such as aluminum(III)
bis(2-methyl-5-quinolinato)-4-phenylphenolate (abbreviation: BAlq),
triazole derivatives, and phenanthroline derivatives such as
2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (abbreviation: BCP) can be
exemplified.

[0205]The thickness of the hole-blocking layer is preferably from 1 to 500
nm, more preferably from 5 to 200 nm, and still more preferably from 10
to 100 nm.

[0206]The hole-blocking layer may have a single layer structure comprising
one kind or two or more kinds of the above materials, or may be a
multilayer structure comprising a plurality of layers having the same
composition or different compositions.

Electron-Blocking Layer:

[0207]The electron-blocking layer is a layer having a function of
preventing the electrons transported from the cathode side to the
light-emitting layer from passing through to the anode side. In the
invention, an electron-blocking layer can be provided as an organic layer
contiguous to the light-emitting layer on the anode side.

[0208]As the examples of the compounds constituting the electron-blocking
layer, for example, the hole-transporting materials described above can
be applied.

[0209]The thickness of the electron-blocking layer is preferably from 1 to
500 nm, more preferably from 5 to 200 nm, and still more preferably from
10 to 100 nm.

[0210]The electron-blocking layer may have a single layer structure
comprising one kind or two or more kinds of the above materials, or may
be a multilayer structure comprising a plurality of layers having the
same composition or different compositions.

Protective Layer:

[0211]In the invention, the organic EL device may be entirely protected
with a protective layer.

[0212]The materials contained in the protective layer are sufficient to
have a function of preventing substances that accelerate deterioration of
the device such as water and oxygen from entering the device.

[0217]A method of sealing with the following shown resin sealing layer is
also preferably used.

Resin Sealing Layer:

[0218]It is preferred to restrain deterioration of performance of the
functional device of the invention due to oxygen and moisture by bringing
into contact with air by the resin sealing layer.

Materials:

[0219]The materials of the resin sealing layer are not especially
restricted, and acrylic resins, epoxy resins, fluorine resins, silicon
resins, rubber resins, and ester resins can be used, and epoxy resins are
preferred in the point of moisture content-preventing function. Of epoxy
resins, thermosetting epoxy resins and photo-curable epoxy resins are
preferred.

Manufacturing Method:

[0220]The manufacturing method of the resin sealing layer is not
especially restricted and, for example, a method of coating a resin
solution, a method of contact bonding or thermal contact bonding of a
resin sheet, and a method of dry polymerization by deposition or
sputtering are exemplified.

Film Thickness:

[0221]The thickness of the resin sealing layer is preferably 1 μm or
more and 1 mm or less, more preferably 5 μm or more and 100 μm or
less, and most preferably 10 μm or more and 50 μm or less. When the
resin sealing layer is thinner than the above range, there is a
possibility that the inorganic film is damaged when a second substrate is
applied. While when the resin sealing layer is thicker than the above
range, the thickness of the organic electroluminescence device itself
becomes thick and a thin film property of the characteristics of the
organic electroluminescence device is impaired.

Sealing Adhesive:

[0222]Sealing adhesive for use in the invention has a function of
preventing water and oxygen from getting in from the edge parts.

Materials:

[0223]As the materials of the sealing adhesives, the same materials as the
materials used in the resin sealing layer can be used. From the point of
waterproofing, epoxy resins are preferred and photo-curable adhesives and
thermosetting adhesives are preferred above all.

[0224]It is also preferred to add fillers to the above materials.

[0225]As the fillers to be added to the sealing agent, inorganic materials
such as SiO2, SiO (silicon oxide), SiON (silicon oxide nitride) and
SiN (silicon nitride) are preferred. By the addition of fillers, the
viscosity of the sealing agent increases, processing suitability is
bettered, and a moisture-proofing property is improved.

Desiccant:

[0226]The sealing adhesive may contain a desiccant. As the desiccant,
barium oxide, calcium oxide, and strontium oxide are preferably used.

[0227]The addition amount of the desiccant to the sealing adhesive is
preferably from 0.01 to 20 mass %, and more preferably from 0.05 to 15
mass %. When the addition amount is less than the above range, the effect
of the addition of the desiccant decreases, while when the amount is
greater than the above range, it is difficult to uniformly disperse the
desiccant in the sealing adhesive, so that not preferred.

Prescription of Sealing Adhesive:

[0228]Polymer Composition, Concentration

[0229]The sealing adhesive is not especially restricted and the above
materials can be used. For example, as the photo-curable epoxy adhesive,
XNR5516 (manufactured by Nagase Chemtex Corporation) can be exemplified,
and it is sufficient that the desiccant is directly added thereto and
dispersed.

[0230]Thickness

[0231]The coating thickness of the sealing adhesive is preferably from 1
μm to 1 mm. When the coating thickness is thinner than that, the
sealing adhesive cannot be coated uniformly and not preferred. When the
thickness is greater than that, a way for water to enter widens, so that
not preferred.

Method of Sealing:

[0232]In the invention, a functional device can be obtained by coating the
sealing adhesive containing the desiccant by means of a dispenser and the
like, and superposing a second substrate thereon after coating and
hardening.

Driving:

[0233]By the application of D.C. (if necessary, A.C. component may be
contained) voltage (generally from 2 to 15 volts) between the anode and
the cathode, or by the application of D.C. electric current, light
emission of the organic electroluminescence device of the invention can
be obtained.

[0234]With respect to the driving method of the organic
electroluminescence device of the invention, the driving methods
disclosed in JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558,
JP-A-8-234685, JP-A-8-241047, Japanese Patent 2784615, U.S. Pat. Nos.
5,828,429 and 6,023,308 can be applied to the invention.

[0235]The luminescence device of the invention can be improved in the
efficiency of collection of light by various known contrivances. For
example, it is possible to improve efficiency of collection of light and
improve external quantum efficiency by processing the shape of the
substrate surface (for example, by forming a minute rugged pattern), by
controlling the refractive indices of the substrate, ITO layer and
organic layers, and by controlling the thicknesses of the substrate, ITO
layer and organic layers.

[0236]The luminescence device of the invention may be what is called top
emission system of collecting light from the anode side.

[0237]The organic EL device of the invention can take a structure of
providing a charge-generating layer between each two layers of a
plurality of light-emitting layers for improving luminous efficiency.

[0238]The charge-generating layer has functions of generating charge
(holes and electrons) at the time of application of electric field and
injecting the generated charge to the layer contiguous to the
charge-generating layer.

[0239]As the material for forming the charge-generating layer, any
material can be used so long as it has the above functions, and the
charge-generating layer may comprise a single compound or a plurality of
compounds.

[0240]Specifically, the material may be a material having conductivity,
may be a material having semi-conductivity such as a doped organic layer,
or may be a material having an electric insulating property, and the
materials disclosed in JP-A-11-329748, JP-A-2003-272860 and
JP-A-2004-39617 can be exemplified.

[0242]As the hole-conductive materials, for example, materials obtained by
doping oxidants having an electron-withdrawing property such as F4-TCNQ,
TCNQ, FeCl3 to hole-transporting organic materials such as 2-TNATA
and NPD, P-type conductive polymers, and P-type semiconductors are
exemplified. As the electron-conductive materials, for example, materials
obtained by doping metals or metallic compounds having a work function of
less than 4.0 eV to electron-transporting organic materials, N-type
conductive polymers, and N-type semiconductors are exemplified. As the
N-type semiconductors, N-type Si, N-type CdS, and N-type ZnS are
exemplified, and the P-type semiconductors, P-type Si, P-type dTe, and
P-type CuO are exemplified.

[0243]Further, an electrically insulating material such as V2O3
can also be used as the charge-generating layer.

[0244]The charge-generating layer may be a monolayer, or a laminate of a
plurality of layers. As the structure of lamination of a plurality of
layers, a layer having a structure of the lamination of a material having
conductivity such as a transparent conductive material or a metallic
material and a hole-conductive material or an electron-conductive
material, and a layer having a structure of the lamination of the
hole-conductive material and the electron-conductive material are
exemplified.

[0245]The thickness is not especially restricted, but is preferably from
0.5 to 200 nm, more preferably from 1 to 100 nm, still more preferably
from 3 to 50 nm, and especially preferably from 5 to 30 nm.

[0246]It is preferred to select the thickness and material of the
charge-generating layer so that the transmittance of visible light is 50%
or more. The forming method of the charge-generating layer is not
especially restricted, and the forming method of the organic layers can
be used.

[0247]The charge-generating layer is formed between each two layers of a
plurality of light-emitting layers, and the anode side and the cathode
side of the charge generating layer may contain materials having a
function of injecting charge to the contiguous layers. For heightening an
electron injecting property to the layer contiguous to the anode side,
electron injecting compounds such as BaO, SrO, Li2O, LiCl, LiF,
MgF2, MgO, CaF2 may be laminated on the anode side of the
charge-generating layer.

[0248]Besides the above description, the materials of the
charge-generating layer can be selected with reference to
JP-A-2003-45676, U.S. Pat. Nos. 6,337,492, 6,107,734 and 6,872,472.

[0249]The organic EL device in the invention may have a resonator
structure. For example, the organic EL device has a multilayer film
mirror comprising a plurality of laminated films different in refractive
index, a transparent or translucent electrode, a light-emitting layer,
and a metal electrode by superposition on a transparent substrate. The
light generated from the light-emitting layer repeats reflection and
resonates between the multilayer film mirror and the metal electrode as
reflectors.

[0250]As another preferred embodiment, a transparent or translucent
electrode and a metal electrode respectively function as reflectors on a
transparent substrate, and light generated from the light-emitting layer
repeats reflection and resonates between them.

[0251]To form a resonance structure, effective refractive indices of two
reflectors, optical path determined by the refractive index and thickness
of each layer between the reflectors are adjusted to be optimal values to
obtain a desired resonance wavelength. The expression of the case of the
first embodiment is disclosed in JP-A-9-180883. The expression of the
case of the second embodiment is disclosed in JP-A-2004-127795.

[0253]As a method of making the organic EL device full colors, for
example, as described in Monthly Display, pp. 33-37 (September, 2000), a
three-color light-emitting method of arranging organic EL devices
emitting lights corresponding to three primary colors (blue (B), green
(G) and red (R)) of colors on a substrate, a white color method of
separating white color emission by an organic EL device for white color
emission to three colors through a color filter, and a color-converting
method of converting blue color emission by an organic EL device for blue
color emission to red (R) and green (G) through a fluorescent dye layer
are known.

[0254]Further, by using in combination of a plurality of organic EL
devices different in luminescent colors capable of obtaining by the above
method, plane light sources of desired luminescent colors can be
obtained. For example, a white emission light source of combining
luminescence devices of blue and yellow luminescence devices, and a white
emission light source of combining luminescence devices of blue, green
and red are exemplified.

EXAMPLES

Synthesis Example 1

Synthesis of Compound C-2 Below (Exemplified Compound 91)

##STR00086##

[0256]To 2,2'-bipyridylsilane is added 1.1 equivalent weight of lithium
tetramethyl piperidide in tetrahydrofuran at -40° C., and the
mixture is subjected to reaction for 30 minutes. Chlorotriphenylsilane
(1.2 equivalent weight) is added to the reaction mixture, followed by
reaction at room temperature for 1 hour or so. The reaction mixture is
hydrolyzed with a sodium hydrogencarbonate aqueous solution to obtain
exemplified Compound 91 in a yield of 50%.

Synthesis Example 2

Synthesis of Compound C-1 Below (Exemplified Compound 116)

##STR00087##

[0258]To 3-bromopyridine is added 1.1 equivalent weight of lithium
diisopropylamide (LDA) in tetrahydrofuran at -70° C., and the
mixture is subjected to reaction for 30 minutes. Dichlorodiphenylsilane
(1.2 equivalent weight) is added to the reaction mixture, followed by
reaction at room temperature for 1 hour or so. The reaction mixture is
hydrolyzed with a sodium hydrogencarbonate aqueous solution to obtain
Intermediate 1 in a yield of 40%. In toluene at II 0° C. in the
presence of a Pd catalyst (palladium
acetate/2-(di-t-butylphosphino)biphenyl), Intermediate 1 is reacted with
phenylboronic acid to obtain exemplified Compound 116 in a yield of 70%.

Manufacture of Organic Electroluminescence Device:

Comparative Example 1-1

[0259]A cleaned ITO substrate is put in a metallizing apparatus, copper
phthalocyanine is deposited on the ITO substrate in a thickness of 10 nm,
NPD ((N,N'-di-α-naphthyl-N,N'-diphenyl)benzidine) is deposited on
the copper phthalocyanine film in a thickness of 40 nm (a hole
transporting layer), Compound B-1 (shown below) and Compound A (shown
below) in proportion of 12/88 (a mass ratio) are deposited thereon in a
thickness of 30 nm (a light-emitting layer), BAlq
(bis(2-methyl-8-quinolinolate)-4-phenylphenolate aluminum) is deposited
thereon in a thickness of 30 nm, Alq (tris(8-hydroxyquinoline) aluminum
complex) is deposited thereon in a thickness of 10 nm (an electron
transporting layer), lithium fluoride is deposited thereon in a thickness
of 3 nm, and aluminum is deposited thereon in a thickness of 60 nm. The
obtained product is put in a glove box replaced with argon gas so as not
to be in contact with air, and sealed with a stainless steel sealing can
and a UV-curing type adhesive (XNR5516HV, manufactured by Nagase Chemtex
Corporation) to obtain an organic electroluminescent device in
Comparative Example 1. The obtained EL device is subjected to application
of DC constant voltage with a source measure unit Model 2400
(manufactured by Toyo Corporation) to emit light. It is confirmed that
the emission of phosphorescence originating in Compound B-1 is obtained.

Examples 1-1 to 1-20 and Comparative Examples 1-2 to 120

[0260]Devices are manufactured and evaluated in the same methods as in
Comparative Example 1-1, except for changing the compounds used in the
light-emitting layer and the electron transporting layer to the compounds
shown in Table 1 below, respectively. It is confirmed that emission of
phosphorescence originating in each light-emitting material used is
obtained. The results obtained are shown in Table 1.

##STR00088## ##STR00089## ##STR00090##

Evaluation of Performances of the Organic Electroluminescence Device:

(a) External Quantum Efficiency

[0261]DC electric current is applied to each device for light emission
with source measure unit Model 2400 (manufactured by Toyo Corporation).
The luminance at that time is measured with a luminometer BM-8
(manufactured by Topcon Corporation). The light emission spectrum and
emission wavelength are measured with a spectrum analyzer PMA-11
(manufactured by Hamamatsu Photonics K.K.). On the basis of these
measurements, external quantum efficiency around 1,000 cd/m2 of
luminance is computed according to a luminance conversion method.

(b) Driving Voltage

[0262]DC voltage is applied to each device so as to reach luminance of
1,000 cd/m2 for light emission, and the applied voltage is taken as
the index of evaluation of driving voltage.

[0263]The results obtained of the above evaluations are shown in Table 1.

[0264]As is apparent from the above results, the devices of the invention
are high in external quantum efficiency and low in driving voltage as
compared with the comparative devices.

Comparative Example 2-1

[0265]Similarly to Comparative Example 1-1, a cleaned ITO substrate is put
in a metallizing apparatus, copper phthalocyanine is deposited on the ITO
substrate in a thickness of 10 nm, NPD
((N,N'-di-α-naphthyl-N,N'-diphenyl)benzidine) is deposited on the
copper phthalocyanine film in a thickness of 40 nm, Compound B-1 and
Compound A in proportion of 12/88 (a mass ratio) are deposited thereon in
a thickness of 30 nm to form a light-emitting layer. BAlq
(bis(2-methyl-8-quinolinolate)-4-phenylphenolate aluminum) is deposited
thereon in a thickness of 40 nm (an electron transporting layer), lithium
fluoride is deposited thereon in a thickness of 3 nm, and aluminum is
deposited thereon in a thickness of 60 nm to obtain a device. The
obtained EL device is subjected to application of DC constant voltage
with a source measure unit Model 2400 (manufactured by Toyo Corporation)
to emit light. It is confirmed that the emission of phosphorescence
originating in Compound B-1 is obtained.

Example 2-1

[0266]A device is manufactured in the same manner as in Comparative
Example 2-1 except that the light-emitting layer in Comparative Example
2-1 (the layer formed by the deposition of Compound 131 and Compound A in
proportion of 12/88 (a mass ratio) in a thickness of 30 nm) is changed to
a layer obtained by depositing Compound B-1, Compound A and Compound C-1
in proportion of 12/75/13 (a mass ratio) in a thickness of 30 nm. As a
result of evaluation in the same manner, it is confirmed that the
emission of phosphorescence originating in Compound B-1 is obtained.

Examples 2-2 to 2-9, and Comparative Examples 2-2 to 2-9

[0267]EL devices are manufactured and evaluated in the same manner as in
Example 2-1 except for changing the electron transporting host material
in the light-emitting layer to the compounds shown in Table 2 below.

Comparative Example 2-4

[0268]An EL device is manufactured and evaluated in the same manner as in
Comparative Example 2-1 except for changing the compound used in the
light-emitting material to Compound B-2. The emission of phosphorescence
originating in the used light-emitting material is obtained.

Example 2-4

[0269]A device is manufactured in the same manner as in Comparative
Example 2-4 except that the light-emitting layer in Comparative Example
2-4 (the layer formed by the deposition of Compound B-2 and Compound A in
proportion of 12/88 (a mass ratio) in a thickness of 30 nm) is changed to
a layer obtained by depositing Compound B-2, Compound A and Compound C-1
in proportion of 12/75/13 (a mass ratio) in a thickness of 30 nm. As a
result of evaluation in the same manner, it is confirmed that the
emission of phosphorescence originating in Compound B-2 is obtained.

Examples 2-5 and 2-6, and Comparative Examples 2-5 and 2-6

[0270]EL devices are manufactured and evaluated in the same manner as in
Example 2-1 except for changing the electron transporting host material
in the light-emitting layer to the compounds shown in Table 2 below.

Comparative Example 2-7

[0271]An EL device is manufactured and evaluated in the same manner as in
Comparative Example 2-1 except for changing the compound used in the
light-emitting material to Compound B-3. The emission of phosphorescence
originating in the used light-emitting material is obtained.

Example 2-7

[0272]A device is manufactured in the same manner as in Comparative
Example 2-7 except that the light-emitting layer in Comparative Example
2-7 (the layer formed by the deposition of Compound 13-3 and Compound A
in proportion of 12/88 (a mass ratio) in a thickness of 30 nm) is changed
to a layer obtained by depositing Compound B-3, Compound A and Compound
C-1 in proportion of 12/75/13 (a mass ratio) in a thickness of 30 nm. As
a result of evaluation in the same manner, it is confirmed that the
emission of phosphorescence originating in Compound B-3 is obtained.

Examples 2-8 and 2-9, and Comparative Examples 2-8 and 2-9

[0273]EL devices are manufactured and evaluated in the same manner as in
Example 2-1 except for changing the electron transporting host material
in the light-emitting layer to the compounds shown in Table 2 below.

[0274]The results of evaluations of the devices in Examples 2-1 to 2-9 and
Comparative Examples 2-1 to 2-9 are shown in Table 2 below.

[0275]As is apparent from the above results, the devices of the invention
are high in external quantum efficiency and low in driving voltage as
compared with the comparative devices.

Comparative Example 3-1

[0276]Similarly to Comparative Example 2-1, a cleaned ITO substrate is put
in a metallizing apparatus, copper phthalocyanine is deposited on the ITO
substrate in a thickness of 10 nm NPD
((N,N'-di-α-naphthyl-N,N'-diphenyl)benzidine) is deposited on the
copper phthalocyanine film in a thickness of 40 nm, Compound B-4 and
Compound A in proportion of 12/88 (a mass ratio) are deposited thereon in
a thickness of 20 nm to form a light-emitting layer. BAlq
(bis(2-methyl-8-quinolinolate)-4-phenylphenolate aluminum) is deposited
thereon in a thickness of 40 nm (an electron transporting layer), lithium
fluoride is deposited thereon in a thickness of 3 mm, and aluminum is
deposited thereon in a thickness of 60 mm to obtain a device. The
obtained EL device is subjected to application of DC constant voltage
with a source measure unit Model 2400 (manufactured by Toyo Corporation)
to emit light. It is confirmed that the emission of phosphorescence
originating in Compound B-5 is obtained.

Example 3-1

[0277]A device is manufactured in the same manner as in Comparative
Example 3-1 except that the light-emitting layer in Comparative Example
3-1 (the layer formed by the deposition of Compound B-5 and Compound A in
proportion of 12/88 (a mass ratio) in a thickness of 30 nm) is changed to
a layer obtained by depositing Compound B-5, Compound A and Compound C-1
in proportion of 12/75/13 (a mass ratio) in a thickness of 30 nm. As a
result of evaluation in the same manner, it is confirmed that the
emission of phosphorescence originating in Compound B-5 is obtained.

Examples 3-2 and 3-3, And Comparative Examples 3-2 and 3-3

[0278]EL devices are manufactured and evaluated in the same manner as in
Example 3-1 except for changing the electron transporting host material
in the light-emitting layer to the compounds shown in Table 3 below.

Comparative Example 3-4

[0279]An EL device is manufactured and evaluated in the same manner as in
Comparative Example 3-1 except for changing the compound used in the
light-emitting material to Compound B-4. The emission of phosphorescence
originating in the used light-emitting material is obtained.

Example 3-4

[0280]A device is manufactured in the same manner as in Comparative
Example 3-4 except that the light-emitting layer in Comparative Example
3-4 (the layer formed by the deposition of Compound B-4 and Compound A in
proportion of 12188 (a mass ratio) in a thickness of 30 nm) is changed to
a layer obtained by depositing Compound B-4, Compound A and Compound C-1
in proportion of 12/75/13 (a mass ratio) in a thickness of 30 nm. As a
result of evaluation in the same manner, it is confirmed that the
emission of phosphorescence originating in Compound B-4 is obtained.

Examples 3-5 and 3-6, and Comparative Examples 3-5 and 3-6

[0281]EL devices are manufactured and evaluated in the same manner as in
Example except for changing the electron transporting host material in
the light-emitting layer to the compounds shown in Table 3 below.

[0282]The results of evaluations of the devices in Examples 3-1 to 3-6 and
Comparative Examples 3-1 to 3-6 are shown in Table 3 below.

[0283]As is apparent from the above results, the devices of the invention
are high in external quantum efficiency and low in driving voltage as
compared with the comparative devices.

Comparative Example 4-1

[0284]A cleaned ITO substrate is put in a metallizing apparatus, copper
phthalocyanine is deposited on the ITO substrate in a thickness of 10 nm,
NPD ((N,N'-di-α-naphthyl-N,N'-diphenyl)benzidine) is deposited on
the copper phthalocyanine film in a thickness of 40 nm, Compound B-6
(shown below) and CBP (4,4'-di(9-carbazoyl)biphenyl) (shown below), and
Compound D-3 in proportion of 12/75/13 (a mass ratio) are deposited
thereon in a thickness of 15 nm (a light-emitting layer), BAlq
(bis(2-methyl-5-quinolinolate)-4-phenylphenolate aluminum) is deposited
thereon in a thickness of 40 nm (an electron transporting layer), lithium
fluoride is deposited thereon in a thickness of 3 nm, and aluminum is
deposited thereon in a thickness of 60 nm to obtain a device. The
obtained EL device is subjected to application of DC constant voltage
with a source measure unit Model 2400 (manufactured by Toyo Corporation)
to emit light. It is confirmed that the emission of phosphorescence
originating in Compound B-3 is obtained.

Examples 4-1 to 4-3, and Comparative Example 4-2

[0285]Devices are manufactured and evaluated in the same methods as in
Comparative Example 41, except for changing the compounds used in the
electron transporting host material in the light-emitting layer to the
compounds shown in Table 4 below. It is confirmed that emission of
phosphorescence originating in each light-emitting material used is
obtained. The results obtained are shown in Table 4.

[0286]As is apparent from the above results, the devices of the invention
are high in external quantum efficiency and low in driving voltage as
compared with the comparative devices.

Comparative Example 5-1

[0287]A cleaned ITO substrate is put in a metallizing apparatus, copper
phthalocyanine is deposited on the ITO substrate in a thickness of 10 nm,
NPD ((N,N'-di-α-naphthyl-N,N-diphenylbenzidine) is deposited on the
copper phthalocyanine film in a thickness of 40 nm, Rubrene (shown below)
and Compound D-2 in proportion of 3/97 (a mass ratio) are deposited
thereon in a thickness of 10 nm (a light-emitting layer), BAlq
(bis(2-methyl-8-quinolinolate)-4-phenylphenolate aluminum)
(bis(6-hydroxyquinoline)-(4-phenylphenol) Al complex salt) is deposited
thereon in a thickness of 40 nm (an electron transporting layer), lithium
fluoride is deposited thereon in a thickness of 3 nm, and aluminum is
deposited thereon in a thickness of 60 nm to obtain a device. The
obtained EL device is subjected to application of DC constant voltage
with a source measure unit Model 2400 (manufactured by Toyo Corporation)
to emit light. It is confirmed that the emission of phosphorescence
originating in Rubrene is obtained.

Examples 5-1 to 5-3

[0288]Devices are manufactured and evaluated in the same methods as in
Comparative Example 5-1, except for changing the compound used as the
host material in the light-emitting layer to the compounds shown in Table
5 below. Emission of phosphorescence originating in each light-emitting
material used is obtained. The results obtained are shown in Table 5.

[0289]As is apparent from the above Examples, by the use of the compounds
in the invention, external quantum efficiency of organic
electroluminescence devices can be improved and driving voltage can be
lowered.

[0290]The organic electroluminescence device in the invention contains at
least one silicon-linking type nitrogen-containing heterocyclic compound
(which is used in the same definition with "the compound of the
invention" in the specification of the invention) represented by any of
formulae (I) to (V) in the organic layer. By containing the compound, the
invention can provide an organic electroluminescence device having high
luminous efficiency (e.g., external quantum efficiency), and excellent in
durability (which is used in the same definition with "the device of the
invention" in the specification of the invention). Further, by the use of
the compound having a special structure, the invention can provide an
organic electroluminescence device capable of emitting light in high
external quantum efficiency in a blue region and at the same time
excellent in durability.

[0291]The entire disclosure of each and every foreign patent application
from which the benefit of foreign priority has been claimed in the
present application is incorporated herein by reference, as if fully set
forth.